The folks over at FreeRepublic.com are discussing the idea in this post: SHOW YOUR COLORS.
The nuts and bolts:
How it works is simple: Proudly carry an American flag with you wherever you are in public. Small parade style flags on sticks would work best for those who commute by bus or subway and those who walk to work. Carry it around with you when you go out for lunch and when you leave work.
Wear red, white and blue patriotic attire. Fly the American flag at your home. Fly an American flag from your car antenna. Tape an American flag in your car window. The goal is to have Old Glory be given the prominence it deserves and to remind everyone--politicians, illegal aliens and their enablers--that the American flag comes first in this country.
Folks have been clamoring for a march to respond to the pro-illegal alien marches. This is a way to do that without having to take time off from work and family responsibilities and still take a stand in public.
Whatever position you hold in the immigration bill battle in congress, I should hope we could all agree that we are first of all Americans, and that the American flag is an appropriate symbol of our allegiance to this country.